Keels

[stevensibs]

I have a 42' brisol trawler project boat that I am going to completely refit from the keel up, but speaking of the keel....the hull is perfect, soda blasted with no blisters, absolutely smooth and solid but in one small spot on the keel bottom amidships where it rests on the wood blocks; the keel is about a foot high at this point and there are several longituinal cracks 12" long and a "slight" curve where the keel rests on the blocks. I mean ever so slight. Thi s is a solid fiberglass hull but I'm wondering, what is the material inside the keel...is it wood and if so, does this slight curve mean a weak spot due to rott? The hull has been resting on these blocks for 8 years, could it be just compressing from the weight a little? Where it rests on the other 2 sets of blocks there is no curve. If it is rotted wood inside, can it be repaired?

 

[JohnP]

Steven,* 8 years with pressure on one point, I don't think this is a sign of internal trouble.* Although the other blocking areas are okay this one may have been carrying more weight.

I would have the yard change the blocking location, maybe put one before and after the affected area.

I doubt if the slight curve will come out anytime soon, but I would be tempted to add another layer or two of glass over the cracks.* Perhaps this would keep water from penetrating the cracks.

Good Luck,** My last boat was an 1985 Bristol Sailboat, I really liked the way it was put together.

JohnP

 

[FF]

Sounds like the yard used less than half the blocking required, and created stress cracks.

I would put a couple of layers of 3/4 oz mat in EPOXY , not pollyester over the cracks .At least 6- 8 inches either side.

The structure is damaged outside to inside ,but probably no danger till a hard grounding.

 

[stevensibs]

Thank you John and FF for your quick reply,

I agree about the "more weight" over these particular blocks, there are a pair of Detroit 6-71's right above them. I was planning on grinding away the gel-coat down past the woven cloth to see if it's cored with fir or lead as I have been told. There has been water sitting in the bilge for 8 years and I'm worried that if there is wood coring inside, it may have been rotted. If that were the case, then the boats back would be broken. Even if that is the case, it can still be repaired, correct? I wish I could contact somebody who worked at Bristol back in 1970 to tell me what's inside.*

This is the begginning of a long 7 year restoration so I will be on here often. LOL

Steve

 

[Delfin]

Steve, good luck on your project. *I don't know how bristol did it, but it was pretty typical for a solid FG hull with keel to have the keel packed with something heavy, then resin poured over the top of it. *On my Cape George with the same internally ballasted keel, they laid lead pigs in, then covered them with resin. *If this is what they did on your boat, then it is basically bullet proof and what you are seeing would be surface stress cracks that may be just cosmetic.

Cheaper approaches were to fill the keel with concrete, which over time cracks and wasn't very satisfactory, or the use of steel boiler punches. It would be nice to find out how this was done on your boat if there is still someone around to ask at Bristol.

*

 

[Anode]

Take a 1/4" drill bit and drill a hole in it two or three inches off the bottom if you suspect moisture in it. You might be surprised at how much water they can accumulate over the years.*And... you might find out what it's ballasted with.


-- Edited by Anode on Friday 13th of May 2011 09:42:02 AM

 

[stevensibs]

Thanks Chip and Delfin. Nice boats on your pics btw.

 

[Delfin]

Anode wrote:
Take a 1/4" drill bit and drill a hole in it two or three inches off the bottom if you suspect moisture in it. You might be surprised at how much water they can accumulate over the years.*And... you might find out what it's ballasted with.



-- Edited by Anode on Friday 13th of May 2011 09:42:02 AM

*That's a great idea. *Patch the hole with epoxy mixed with silicon.

 

[FF]

There has been water sitting in the bilge for 8 years and I'm worried that if there is wood coring inside, it may have been rotted.

Wood that is saturated does not rot.

It is unheard of to use wood in the keel area, esp for a respected builder.

 

[Jay N]

stevensibs wrote:
I have a 42' brisol trawler project boat that I am going to completely refit from the keel up, but speaking of the keel....the hull is perfect, soda blasted with no blisters, absolutely smooth and solid but in one small spot on the keel bottom amidships where it rests on the wood blocks; the keel is about a foot high at this point and there are several longituinal cracks 12" long and a "slight" curve where the keel rests on the blocks. I mean ever so slight. Thi s is a solid fiberglass hull but I'm wondering, what is the material inside the keel...is it wood and if so, does this slight curve mean a weak spot due to rott? The hull has been resting on these blocks for 8 years, could it be just compressing from the weight a little? Where it rests on the other 2 sets of blocks there is no curve. If it is rotted wood inside, can it be repaired?

*Crushing damage from inadequate keel support is not uncommon.* In my case, there were three bearing areas of 12" wide blocking along a 34' keel that were apparently regularly used by the previous owner/shipyard.* While the bottom is solid fiberglass in this area, the keel is hollow and filled with a foam that will not absorb water.

After reblocking, the area was significantly scarffed and re-inforced with a proper fiberglass repair.

The subsequent blocking area was altered and elongated by orienting the blocking fore-and-aft which provides much improved support.